TOPIC: Before I pull the trigger

Last week I finished putting the '58 Johnson RDS-20 together and got her running fairly well, needs tweaking when it gets in real water.
Question is it seems like the fuel pump cannot keep up with the flow needed. the filter bowl will fill up and the motor runs for a minute and then the glass shows that fuel is not pumping fast enough. I have two pumps that I can switch out but both diaphragms seem like they are stretched out. No holes or cracks but just sorta rubbery. Would this be the problem? Looks like a result of ethanol.
Marineengine.com has them $7.99.
While running on the stand I put the fuel line in a one gallon container about 2' below the motor. Thought this might be the problem but when I moved the fuel level with the motor is still did the same thing.
This is an old photo before the rebuild.
Cal

63 Sabre,

You may want to LOOK FOR NO-alcohol fuel in your area IF there is any.
OR
Contact TallTexan and ask him how to get the ethanol OUT of your gasoline.
("Our" outboards were never designed for ethanol.)

just my opinions, satx

There's several stations around me that have ethanol free stuff. It's what I use in my 100hp golden meteor.
Age of the pumps probably isn't any help either.
I'll go ahead and get a new diaphragm, sure won't hurt anything.
Just needed a second opin.
Thanks.

You may try hand pumping the primer bulb when it starts to stumble, to see if it takes up for the pump. Also, sometimes it's the primer bulb itself. I've heard of guys rebuilding the engine, then find out it only needed a priming bulb...

She pumps right up with the bulb. New bulb, hose and connections. The price of those things is going ballistic! Used to be able to pick up a whole new setup for around $15 now it's more like $50. New 6 gallon plastic tank in a box store is over $50. Picked up two 6 gallon tanks on craigs for $15 each a few weeks ago. Ordered the diaphragm this morning.

The fuel filter bowl does not stay full during normal operation, sounds like you have nothing to worry about. Give it a try on a boat I'd bet it's fine.
Al

Gee Al, wish you would have said something before I ordered a new one
Only kidding. Last engine I had with a fuel bowl was a snow blower from the 70's. Personally I think they were an important part of the fuel system. Good indication if there is dirt, water, or any other contaminants in the fuel and...you can see if the filter is dirty.
Either way, nothing wrong with installing a new one. I'll keep the old one for a spare.